WM-N-Fan,
I live in Westminster, and I've never seen the Hagerstown yard, except in some photos on the Hagerstown Roundhouse web site. So, it's all in my imagination. I do have a turntable and roundhouse in the yard.
I have limited space, so the same yard is also Baltimore. Whether a given loco or car is in one city or the other depends on the waybill it carries at the moment. Switching in the yard when it's "Hagerstown" is done by a WM BL-2. A B&O GP-38 does the duty when the yard is in its "Baltimore" mode. The "Baltimore" yard is simply a terminus, so there's nothing complicated that's supposed to go there. A freight car goes to Baltimore from Hagerstown, gets unloaded (by flipping over it's waybill in the car card slot and having any load it actually carries removed by the great 5-fingered crane in the sky), then gets hauled back to "Hagerstown" when the next B&O freight heads in that direction.
Traffic to Frostburg, Thurmont, Union Bridge and Westminster is all handled by WM locomotive power.
The yard has an eastbound and a westbound track. In "Hagerstown" mode, the eastbound track takes you to Frostburg. In "Baltimore" mode, the same track runs past Westminster, then Union Bridge, then Thurmont, then on to Hagerstown. I could say similar things about the westbound track.
Mine is a shelf-type layout, 30 inches wide, 10.5 feet along one side and 9 feet along the other. Trains do most of their inter-town travel by making laps around the perimeter (plus one interior shortcut). So, for example, when a train heads east out of Baltimore to head to Hagerstown, I have to blink my eyes and pretend not to be looking when I reach the turnout to Frostburg. It's not supposed to be there <chuckle>.
My layout is far from complete, the trackage I've talked about is complete, though I want to expand the yard a bit. Mostly what you see when you view it is the tracks, a kit-built roundhouse with turntable, and some scratchbuilt buildings. The buildings include a freight house in Hagerstown, Bowman's feeds in Westminster, a grain elevator in Thurmont and a coal elevator in Frostburg. The rest of what you see is a flat expanse of blue extruded styrofoam. I'll make some photos and try to load them on here, when I get a chance.
I've only been model railroading since last summer. So far, I've only actually visited the local tracks around Westminster and Union Bridge. By the way, the WM Historical Society has an excellent museum with layouts under construction. This is housed in the old Union Bridge station. It's open on Sundays and admission is free.
I had a great-uncle who was station master at the Point-of-Rocks station, so I want to visit that when the weather improves. Also, I want to get over to Hagerstown one day in June. Do you live around there? Perhaps I could pick your brain to find the best directions to railroad sites in that part of MD.
Sorry to be so long-winded. Cheers.